feat: strategy knobs in the database — config_overrides table, admin-managed

Owner preference: the bulk of TRADING_*/TRIGGER_* logic switches should live
in the DB, not the compose file (keys + connection info stay in compose —
the DB address cannot live inside the DB, and secrets don't belong in a
table the stack can SELECT). Precedence at boot: compose env < overrides.env
< config_overrides table; every entrypoint already routes through
env_overrides.load(), which now applies the table last. Admin /api/config
and profile-apply write the table (secrets whitelist unchanged); the config
page shows source=database. DB down = silent fall-through to file/compose,
boot never blocks on config. One-shot migration:
  python -m runtime.env_overrides seed-from-env
run in any stack container to copy its current effective knobs into the
table, after which the compose lines are dead weight strippable at the next
redeploy.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

admin_api.py

@@ -123,8 +123,9 @@ def _safe_overrides() -> dict:
     """Overrides for API responses with secret VALUES redacted — a /api/mode live
     switch writes ALPACA_LIVE_* into overrides.env; without this they'd echo back
     in every /api/status and /api/config response."""
+    merged = {**env_overrides.read_overrides(), **env_overrides.read_db_overrides()}
     return {k: ("***" if any(m in k for m in SECRET_MARKERS) else v)
-            for k, v in env_overrides.read_overrides().items()}
+            for k, v in merged.items()}
 
 
 def _editable(key: str) -> bool:
@@ -169,8 +170,10 @@ def effective_config() -> dict:
     both surface as ``compose``); a documented .env.example key that is absent
     surfaces as ``missing`` (drift). Secret values are masked."""
     overrides = env_overrides.read_overrides()
+    db_overrides = env_overrides.read_db_overrides()
     example = _env_example_keys()
-    keys = set(example) | set(overrides) | {k for k in os.environ if _editable(k)}
+    keys = (set(example) | set(overrides) | set(db_overrides)
+            | {k for k in os.environ if _editable(k)})
     out: dict[str, dict] = {}
     for key in sorted(keys):
         value = os.environ.get(key)
@@ -179,7 +182,8 @@ def effective_config() -> dict:
                         "source": "missing" if key in example else "unset",
                         "drift": key in example}
             continue
-        source = "overrides.env" if key in overrides else "compose"
+        source = ("database" if key in db_overrides
+                  else "overrides.env" if key in overrides else "compose")
         out[key] = {"value_masked": _mask_value(key, str(value)), "source": source}
     return out
 
@@ -350,9 +354,14 @@ class Handler(BaseHTTPRequestHandler):
             bad = [k for k in list(updates) + list(deletes) if not _editable(k)]
             if bad:
                 return self._send(400, {"error": f"not editable: {bad}"})
-            merged = env_overrides.write_overrides(
-                {**{k: str(v) for k, v in updates.items()},
-                 **{k: None for k in deletes}})
+            # knobs go to the DATABASE (owner-facing store; whitelist above
+            # already refused secrets). overrides.env keeps secrets/bootstrap.
+            try:
+                merged = env_overrides.write_db_overrides(
+                    {**{k: str(v) for k, v in updates.items()},
+                     **{k: None for k in deletes}})
+            except Exception as exc:  # noqa: BLE001
+                return self._send(502, {"error": f"db write failed: {exc}"})
             return self._send(200, {"ok": True, "overrides": merged,
                                     "note": "restart affected services to apply"})
 
@@ -362,7 +371,7 @@ class Handler(BaseHTTPRequestHandler):
             if not prof:
                 return self._send(404, {"error": f"no profile {name!r}"})
             knobs = {k: str(v) for k, v in prof.items() if not k.startswith("_")}
-            merged = env_overrides.write_overrides(knobs)
+            merged = env_overrides.write_db_overrides(knobs)
             return self._send(200, {"ok": True, "applied": name, "overrides": merged,
                                     "note": "restart the loop to apply"})